The invention relates to a first-fail-safe electromotive furniture drive according to the preamble of claim 1.
Different designs of these types of electromotive furniture drives for adjustment of diverse furniture are known. These furniture include among others reclining and seating furniture, such as for example beds, slatted frames, television chairs. In particular in home and clinical care as well as in medicine, electromotive furniture drives are used in the corresponding furniture, for example in care beds and hospital beds. In these areas of use, pertinent rules, norms and laws apply wherein the so called first-fail-safety is very important.
First-fail-safety means that in the case of a first failure, for example of a component, no danger is created for the user and no undesired and/or unintended functions and/or unintended movements of movable furniture elements are caused, which create hazards.
EP 1 341 201 A2 describes an electromotive adjustment arrangement for furniture with a release relay via the contacts of which an overall motor current flows, which is then conducted to a further relay arrangement for impinging on a drive motor for causing an adjustment function. Assigned to this releasing relay is a function monitoring component, which controls the functionality of the releasing relay.
DE 103 41 705 A1 describes an arrangement for the operation of an electronically adjustable seat and/or reclining furniture with a device for supply current activation with a relay. The arrangement has a switching means for switching the relay for supply current activation, wherein the switching means have switching contacts which are independent of one another and can be operated simultaneously.